Person:
Ábalos Álvarez, Marta

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First Name
Marta
Last Name
Ábalos Álvarez
URI
https://hdl.handle.net/20.500.14352/75077
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Físicas
Department
Física de la Tierra y Astrofísica
Area
Física de la Tierra
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2022 - 20233
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Start date: 2020 × Subject: 550.3 ×

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Now showing 1 - 3 of 3
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    Stratospheric water vapor affecting atmospheric circulation
    (Nature Communications, 2023) Charlesworth, Edward; Plöger, Felix; Birner, Thomas; Baikhadzhaev, Rasul; Ábalos Álvarez, Marta; Abraham, Nathan Luke; Akiyoshi, Hideharu; Slimane Bekki, Slimane; Dennison, Fraser; Jöckel, Patrick; Keeble, James; Kinnison, Doug; Morgenstern, Olaf; Plummer, David; Rozanov, Eugene; Strode, Sarah; Zeng, Guang; Egorova, Tatiana; Riese, Martin
    Water vapor plays an important role in many aspects of the climate system, by affecting radiation, cloud formation, atmospheric chemistry and dynamics. Even the low stratospheric water vapor content provides an important climate feedback, but current climate models show a substantial moist bias in the lowermost stratosphere. Here we report crucial sensitivity of the atmospheric circulation in the stratosphere and troposphere to the abundance of water vapor in the lowermost stratosphere. We show from a mechanistic climate model experiment and inter-model variability that lowermost stratospheric water vapor decreases local temperatures, and thereby causes an upward and poleward shift of subtropical jets, a strengthening of the stratospheric circulation, a poleward shift of the tropospheric eddy-driven jet and regional climate impacts. The mechanistic model experiment in combination with atmospheric observations further shows that the prevailing moist bias in current models is likely caused by the transport scheme, and can be alleviated by employing a less diffusive Lagrangian scheme. The related effects on atmospheric circulation are of similar magnitude as climate change effects. Hence, lowermost stratospheric water vapor exerts a first order effect on atmospheric circulation and improving its representation in models offers promising prospects for future research.
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    Very short-lived halogens amplify ozone depletion trends in the tropical lower stratosphere
    (Nature Climate Change, 2023) Ábalos Álvarez, Marta; Villamayor Moreno, Julián; Iglesias Suárez, Fernando; Cuevas, Carlos A.; Fernandez, Rafael P.; Li, Qiny; Hossaini, Ryan; Chipperfield, Martyn P.; Kinnison, Douglas E.; Tilmes, Simone; Lamarque, Jean-Francois; Saiz López, Alfonso
    In contrast to the general stratospheric ozone recovery following international agreements, recent observations show an ongoing net ozone epletion in the tropical lower stratosphere (LS). This depletion is thought to be driven by dynamical transport accelerated by global warming, while chemical processes have been considered to be unimportant. Here we use a chemistry–climate model to demonstrate that halogenated ozone-depleting very short-lived substances (VSLS) chemistry may account for around a quarter of the observed tropical LS negative ozone trend in 1998–2018. VSLS sources include both natural and anthropogenic emissions. Future projections show the persistence of the currently unaccounted for contribution of VSLS to ozone loss throughout the twenty-first century in the tropical LS, the only region of the global stratosphere not projecting an ozone recovery by 2100. Our results show the need for mitigation strategies of anthropogenic VSLS emissions to preserve the present and future ozone layer in low latitudes.
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    Boreal winter stratospheric climatology in EC-EARTH: CMIP6 version
    (Climate dynamics, 2022) Palmeiro, Froila M.; García Serrano, Javier; Rodrigo, Mario; Ábalos Álvarez, Marta; Christiansen, Bo; Yang, Shuting
    The performance of the European Consortium Earth-system model (EC-EARTH) in the boreal winter stratosphere is comprehensively assessed for the first time, in particular its version 3.3 that contributes to CMIP6. A 100-year long simulation with prescribed climatological boundary conditions and fixed radiative forcing, representative of present-day climate, is used to evaluate the simulation of the climatological stratospheric circulation and to identify model biases. Results show that EC-EARTH has a large issue with the vertical distribution of stratospheric temperature from the tropics to mid-latitudes, seemingly linked to radiative processes of ozone, leading to a biased warm middle-upper stratosphere. Associated with this model bias, EC-EARTH simulates a stronger polar vortex at upper-stratospheric levels while the Brewer-Dobson circulation at middle/lower levels is weaker than reanalysis. The amplitude of the climatological planetary waves is overall underestimated, but the magnitude of the background wave injection from the troposphere into the stratosphere is overestimated, related to a weaker polar vortex at lower-stratospheric levels and, thus, a less effective wave filtering. This bias in the westerly flow could have a contribution from parameterized waves. The overestimation of background wave driving is maximum in early-winter, and may explain the overestimated frequency of sudden stratospheric warmings at this time, as compared to reanalysis. The spatial distribution of wave injection climatology has revealed a distinctive role of the climatological planetary waves: while large-scale waves (wavenumbers 1-2) dominate the eddy heat flux over the North Pacific, small-scale waves (wavenumbers 3-4) are responsible for the doubled-lobe structure of the eddy heat flux over Eurasia. EC-EARTH properly simulates this climatological feature, although overestimates its amplitude over central Eurasia.